Controllable Conversion of CdNCN Nanoparticles into Various Chalcogenide Nanostructures for Photo-driven Applications

Graphical Ball control : A new synthetic method based on CdNCN nanoparticle anion exchange reactions was developed to access solid or hollow CdSe nanocrystals with tunable size, which exhibit narrow width of photoluminescence features. The obtained CdNCN@CdS heterostructures with modulated shell/core thickness show a remarkable improvement in photocatalysis compared to CdS or CdNCN NPs of similar size. Semiconductor nanocrystals of tunable shell/core configurations have great potential in photo-driven applications such as photoluminescence and photocatalysis, but few strategies realize a controllable synthesis with respect to both the size of the core and the shell with high crystallinity. Here, a new synthetic method based on cadmium cyanamide (CdNCN) nanoparticle anion exchange reactions was developed to access solid or hollow CdSe nanocrystals with tunable size and CdNCN@CdS heterostructures with modulated shell/core thickness. The gradual shift and narrow width of photoluminescence features demonstrate the high crystallinity and monodispersity of the resulting CdSe nanocrystals. In the CdNCN@CdS heterostructures, synergistic effects of the photocarrier separation is observed between the CdS shell and CdNCN core, which leads to great improvement in photocatalysis with optimized shell/core ratio.